Make build of pluto and starter optional on Android.

Android.mk.in

@@ -1,6 +1,9 @@
 LOCAL_PATH := $(call my-dir)
 include $(CLEAR_VARS)
 
+# whether starter is built.  allows to control the daemons from the command line
+strongswan_BUILD_STARTER := true
+
 # whether pluto (IKEv1 daemon) is built.  charon (IKEv2) is always enabled
 strongswan_BUILD_PLUTO := true
 
@@ -92,16 +95,27 @@ strongswan_CFLAGS := \
 strongswan_CFLAGS += \
 	-DHAVE_IN6ADDR_ANY
 
+strongswan_BUILD := \
+	charon \
+	libcharon \
+	libhydra \
+	libstrongswan \
+	libtncif
+
+ifneq ($(strongswan_BUILD_STARTER),)
+strongswan_BUILD += \
+	libfreeswan \
+	starter \
+	stroke \
+	ipsec
+endif
+
+ifneq ($(strongswan_BUILD_PLUTO),)
+strongswan_BUILD += \
+	libfreeswan \
+	pluto \
+	whack
+endif
+
 include $(addprefix $(LOCAL_PATH)/src/,$(addsuffix /Android.mk, \
-		charon \
-		libcharon \
-		libhydra \
-		libstrongswan \
-		libtncif \
-		libfreeswan \
-		pluto \
-		stroke \
-		whack \
-		starter \
-		ipsec \
-	))
+		$(sort $(strongswan_BUILD))))